Hi Felipe, On Monday 23 May 2016 12:48 PM, Felipe Balbi wrote: > > Hi Kishon, > > Kishon Vijay Abraham I <kishon@xxxxxx> writes: >> Hi Felipe, >> >> On Friday 20 May 2016 12:06 AM, Felipe Balbi wrote: >>> >>> Hi, >>> >>> Tony Lindgren <tony@xxxxxxxxxxx> writes: >>>> * Peter Ujfalusi <peter.ujfalusi@xxxxxx> [160519 01:10]: >>>>> On 05/18/2016 10:30 PM, Tony Lindgren wrote: >>>>>> Ideally the adma support would be a separate loadable module, >>>>>> similar how the cppi41dma is a child of the OTG controller. >>>>> >>>>> The Master DMA is part of the hsmmc IP block. If the same ADMA module is >>>>> present on other IPs it might be beneficial to have a helper library to handle >>>>> it (allocating the descriptor pool, wrinting, updating descriptors, etc). >>>> >>>> OK. Yeah if it's part of the MMC controller it makes no sense to >>>> separate it. So then the conecrns are using alternate DMA >>>> implementations and keeping PM runtime working :) >>>> >>>> BTW, Felipe mentioned that the best thing to do in the long run would >>>> be to set up sdhci-omap.c operating in ADMA mode. >>>> >>>> Felipe, care to summarize what you had in mind? >>> >>> yeah, just write a new sdhci-omap.c to start moving away from >>> omap-hsmmc.c, just like it was done for 8250-omap. >>> >>> At the beginning, it could be just the bare minimum to get it working >>> and slowly move over stuff like pm runtime, dmaengine, PIO. Move more >>> platforms over to that driver and, eventually, get rid of omap-hsmmc.c >>> altogether. >>> >>> That way, development can be focussed on generic layers (SDHCI) to which >>> OMAP MMC controller is compliant (apart from the VERSION register >>> quirk). >> >> About an year back, when I tried using SDHCI for OMAP I ran into >> issues and was not able to get it working. IIRC SDHCI_PRESENT_STATE >> (or OMAP_HSMMC_PSTATE) was not showing the correct state for card >> present and is unable to raise an interrupt when a card is inserted. I >> didn't debug this further. > > I'd say this is a bug in hsmmc. I remember seeing some bits in some > TI-specific register (before SDHCI address space starts) which can be > used to keep parts of SDHCI powered on exactly so normal WP and CD pins > work as expected. > > In any case, adding support for GPIO-based card detect to generic SDHCI > shouldn't be too difficult :-) > >> It also kept me wondering why gpio interrupt was always used for card >> detect instead of using mmci_sdcd line of the controller. > > Probably a really, really old bug which nobody ever debugged properly ;-) > > ps: you don't need that ADMA2 DT property, btw. There's a bit in another > register which you can check if $this controller was configured with > ADMA2 support or not. IIRC, OMAP5's TRM describes them. hmm yeah.. Should be the MADMA_EN in MMCHS_HL_HWINFO. Thanks Kishon -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
